The formation of constructions having a material microstructure made up or two or more different layers, regions, and/or phases of materials is well known. Such constructions are intentionally engineered in this fashion to provide a desired mix of physical, mechanical and/or thermal properties within the material microstructure, making it better equipped to handle a particular end use application. In order to provide such desired properties in a predictable and consistent manner, it is desired that the characteristics, e.g., the thickness, volume or area, of such layers, regions and/or phases within the microstructure be controlled for consistency.
It is, therefore, necessary that the desired characteristics of such layers, regions, and/or phases of materials within the construction be measured for the purpose of both controlling the process that is used to make the construction to thereby ensure its consistency, and for controlling the quality or ability of the construction to perform as expected. Methods useful for measuring the thickness or variation in the thickness of a region, layer or phase within a material construction will vary depending on the nature of the construction. For material constructions used in tooling, wear, and/or cutting applications provided in the form of an ultra-hard polycrystalline material, e.g., comprising polycrystalline diamond, a useful method for measuring the thickness or determining the or variation of thickness of one or more regions within the construction is by destructive method or destructive testing.
Destructive testing requires that the construction itself be cut or otherwise treated in a manner that physically exposes the targeted regions to be measured or evaluated by visual inspection. In an example embodiment, where the construction is one comprising an ultra-hard polycrystalline material such as diamond or cubic boron nitride, the construction itself is cut, e.g., in half, so that the different layers, regions and/or phases forming the construction can be viewed visually for purposes of measuring the thickness or variation of thickness of the regions. In an example embodiment, such visual indication is made with the assistance of a magnifying device such as a microscope, e.g., a scanning electron microscope.
While such destructive test method is useful for determining the thickness or variation of thickness within a construction, it is time consuming in that after the part is cut it must usually be further prepared by grinding, polishing or the like, then mounted for microscopic evaluation. Further, such microscopic evaluation is oftentimes taken along a number of different points to gather sufficient measurement data to arrive at a numerical value that is representative of the measurement date for the entire part, e.g., an average region thickness throughout the part. Still further, the use of such destructive test method is expensive in that it requires that the part being evaluated be destroyed, thereby adversely impacting the economics associated with manufacturing the parts.
It is, therefore, desired that a method be developed that is capable of measuring the a desired characteristic of a material construction, e.g., the thickness or variation of thickness of one or more region, volume, and/or phase within a material construction such as an ultra-hard polycrystalline construction, in a manner that is not destructive. It is further desired that such a method be capable of providing such desired measurement information in a manner that has a known degree of accuracy. It is further desired that the method be capable of providing an indication of the desired characteristic that is representative of the entire construction or part being measured. It is still further desired that the method be capable of providing such measurement information in a manner that is efficient to permit testing on a large-scale production basis.